Datasheet

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DESCRIPTION/ORDERING INFORMATION (CONTINUED)
SN74CB3Q3253
DUAL 1-OF-4 FET MULTIPLEXER/DEMULTIPLEXER
2.5-V/3.3-V LOW-VOLTAGE HIGH-BANDWIDTH BUS SWITCH
SCDS145A – OCTOBER 2003 – REVISED MARCH 2005
The SN74CB3Q3253 is organized as two 1-of-4 multiplexers/demultiplexers with separate output-enable(1 OE,
2 OE) inputs. The select (S0, S1) inputs control the data path of each multiplexer/demultiplexer. When OE is low,
the associated multiplexer/demultiplexer is enabled, and the A port is connected to the B port, allowing
bidirectional data flow between ports. When OE is high, the associated multiplexer/demultiplexer is disabled, and
a high-impedance state exists between the A and B ports.
This device is fully specified for partial-power-down applications using I
off
. The I
off
circuitry prevents damaging
current backflow through the device when it is powered down. The device has isolation during power off.
To ensure the high-impedance state during power up or power down, OE should be tied to V
CC
through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
ORDERING INFORMATION
T
A
PACKAGE
(1)
ORDERABLE PART NUMBER TOP-SIDE MARKING
QFN – RGY Tape and reel SN74CB3Q3253RGYR BU253
SSOP (QSOP) – DBQ Tape and reel SN74CB3Q3253DBQR BU253
–40 ° C to 85 ° C Tube SN74CB3Q3253PW
TSSOP – PW BU253
Tape and reel SN74CB3Q3253PWR
TVSOP – DGV Tape and reel SN74CB3Q3253DGVR BU253
(1) Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at
www.ti.com/sc/package.
FUNCTION TABLE
(EACH MULTIPLEXER/DEMULTIPLEXER)
INPUTS INPUT/OUTPUT
FUNCTION
OE S1 S0 A
L L L B1 A port = B1 port
L L H B2 A port = B2 port
L H L B3 A port = B3 port
L H H B4 A port = B4 port
H X X Z Disconnect
2